Apparatus for making brake shoes

ABSTRACT

A HEATED BRAKE SHOE PRESS HAS A LONGITUDINAL OPEN END CAVITY DEFINED BY A BASE AND COVER. ONE END OF THE CAVITY MAY BE CLOSED BY A MOVABLE PLATEN. A MOVABLE PLUNGER PROJECTS INTO THE OTHER END OF THE CAVITY AND IS SLIDEABLY ENGAGED WITH THE CAVITY THROUGHOUT ITS LENGTH. INSERTS AND LINERS ARE SLIDEABLY ENGAGED IN THE CAVITY IN A GIVEN ORDER AND DEFINE A PLURALITY OF MOLDING CAVITIES THAT ARE FILLABLE WITH MOLDABLE MATERIAL. THE HEAT, AND THE PRESSURE EXERTED BY TEH PLUNGER CONFIGURES THE MATERIAL IN THE MOLDING CAVITIES TO A SHAPE DEFINED BY THE INSERTS AND   LINERS. AFTER FORMING, THE PLATEN MAY BE MOVED TO AN OPEN POSTION AND THE INSERTS AND CONFIGURED MATERIAL MAY BE PUSHED OUT OF THE CAVITY BY THE PLUNGER.

Sept. 28, 1971 E. RATCLIFFE APPARATUS FOR MAKING BRAKE SHOES 2 Sheets-Sheet 1 Filed Jan. 23, 1969 fill/a ain Jada/m4 aizlzalfle Sept. 28, 1971 RATCUFFE 3,608,140

APPARATUS FOR MAKING BRAKE SHOES Filed Jan. 23, 1969 2 Sheets-Shoot 2 United States Patent l 3,608,140 APPARATUS FOR MAKING BRAKE SHOES Edward Ratclitfe, Mont St. Hilaire, Quebec, Canada, assignor to Amsted Industries Incorporated, Chicago,

Filed Jan. 23, 1969, Ser. No. 793,432 Int. Cl. 133% 11/06 US. Cl. 18--17R Claims ABSTRACT OF THE DISCLOSURE A heated brake shoe press has a longitudinal open end cavity defined by a base and cover. One end of the cavity may be closed by a movable platen. A movable plunger projects into the other end of the cavity and is slideably engaged with the cavity throughout its length. Inserts and liners are slideably engaged in the cavity in a given order and define a plurality of molding cavities that are fillable with moldable material. The heat, and the pressure exerted by the plunger configures the material in the molding cavities to a shape defined by the inserts and liners. After forming, the platen may be moved to an open position and the inserts and configured material may be pushed out of the cavity by the plunger.

This invention relates to brake shoe presses for making composition brake shoes.

The present invention may be utilized to produce composition brake shoes having close tolerances and a uniform density in a minimal amount of time and with a minimal amount of labor. The brake shoe press may be further quickly and easily converted to accommodate a number of sizes and shapes of brake shoes.

The foregoing and other objects and advantages of the invention will become apparent from the following description and the accompanying drawings, wherein:

FIG. 1 is a fragmentary, top plan view of a brake shoe press embodying features of the invention;

FIG. 2 is a sectional view taken on line 2-2 of FIG.

FIG. 3 is an end view of FIG. 1; and

FIG. 4 is a sectional view taken on line 4-4 of FIG. 2.

Referring now to the drawings wherein FIG. 1 illustrates a brake shoe press 6 comprising a mold 8 and a ram unit 10 that are mounted on a frame 12.

The mold 8 includes a cover 14 and a base 16 that define an elongated, open end cavity 18 (FIG. 2). The cavity 18 may be bound on three sides by the base 16 and on the fourth side by the cover 14. In a preferred embodiment the opposed sides and the upper and lower surfaces of cavity 18 are substantially flat and smooth and are respectively parallel to their opposed surface in any plane defining the longitudinal axis of the cavity. Beveled interlocking lips 20 and 22 respectively on the cover 14 and the base 16 form a tight, quick release connection.

The cover 14 may be secured to the base 16, among other ways, by clamps 24 which may include opposed clamping arms 26 and 28. Each arm 26, 28 may be pivotally connected at 30 intermediate its upper and lower ends 32 and 34 between a pair of spaced supports 36 that are mounted on the cover 14. The arms 26 and 28 may be further pivotally connected at their upper ends 32 to a known hydraulic cylinder and ram device 38. Angular hook shaped members 40 may be located on the lower ends 34 of respective arms 26, 28 and may be engageable with corresponding angular retaining plates 42 located on opposite sides of the base 16.

A series of clamps 24, e.g., six, may be located longitudinally along the mold 8 for applying locking pres- 3,608,140 Patented Sept. 28., 1971 sure between the cover 14 and the base 16. In clamping, each hydraulic device 38 forces the upper ends 32 0f the arms 26 and 28 outwardly, pivoting the arms 26 and 28 about connections 30 and forcing the angular hooks 40 into tight mating engagement with the angular plates 42. The hooks 40 tend to force the base 16 upwardlv while the supports 36 tend to move the cover 14 downwardly. In unlocking, the hydraulic devices 38 move the upper ends 32 of the arms 26 and 28 toward each other pivoting the arms 26 and 28 at 30 and thereby moving the books 40 away from the base 16 and freeing the cover 14 for movement. Retaining blocks 44 may be located on opposite sides of the cover 14 to engage the upper portions of the respective arms 26 and 28 and aid in forcing both books 40 on each clamp 24 away from the plates 42.

The cover 14 may be moved away from the base 16. among other ways, by a hydraulic cylinder and ram device 46 pivotally secured to the frame 12 at 48 (FIG. 3). Levers .50 secured to the cover 14 longitudinally along the mold 8 may be pivotally fulcrumed by a rod 52 to members 54 connected to the frame 12. The lower end 56 of at least one lever may be pivotally connected to a device 46.

In moving the cover 14 away from the base 16, device 46 forces the lower end 56 of its lever 50 toward the frame 12 (FIG. 3), thereby moving the unclamped cover 14 upwardly and away from the base 16. Engagement of the cover 14 with the base 16 is accomplished in a reverse manner.

The rearward end 58 of the cavity 18 may be enclosed by an end wall 60. The wall 60 may comprise a platen 62 (FIGS. 1, 3, and 4) slideably engaged in bushed opposed slots 64 (FIG. 4, only one shown) located in the base 16. The platen 62 may have a forward section 66 that lies proximate one end of the cavity 18. Corresponding, opposed hydraulic cylinders and ram devices 68 may be mounted respectively on opposite sides of the base 16 and engaged with cross bars 70 secured to the upper end of the platen 62. Actuation of the cylinders 68 will raise the platen 62, opening one end of the cavity 18, or will lower the platen 62, enclosing one end of the cavity 18.

The forward end 71 of the cavity 18 may contain a removable guide feed plunger 72 actuated by a pair of corresponding hydraulic cylinder and ram devices 74 mounted on the frame 12. The devices 74 will move the plunger 72 through the cavity 18 from the forward end 71 to the rearward end 58.

A heating unit is shown associated with mold 8 (FIG. 2) in the form of a known thermal liquid heater having passages 76 and 78 respectively located in the cover 14 and base 16. A known heating fluid may be circulated through these passages 76 and 78 in a known manner to heat the mold 8. The mold 8 may also be heated in other ways, e.g., by electric heating elements located in the cover 14 and base 16.

In operation, the mold 8 is heated to a given temperature, e.g., 350 F., by the heating unit. When the platen 62 closed, the cover 14 is pivoted open and the plunger 72 is moved to the forward end 71 of the cavity 18 (FIG. 1). Side and bottom liners '80 and 82, respectively, are placed within the cavity 18 (FIG. 2). Various size liners may be used in making various size brake shoes. A given number of inserts 84, e.g., eight, each comprising a front die 86, a rear die 88 and a spacer 90, may then be sequentially placed in the cavity 18 (FIG. 1). The front and rear dies 86 and 88 have a given configuration that defines a cavity 89 having a known brake shoe design therebetween. If desired, the configurations on dies 86 and 88 (FIG. 1) may be located on the front and rear surface of a single insert block. All of the various brake shoe defining parts, .80, '82 and 84, may be treated with a known suitable parting agent.

Composition, in the form of pre-formed briquets or loose aggregate, of known thermosetting brake shoe material may be placed in each cavity 89. A top liner 92 may be located over the inserts 84 and the composition filled cavities 89 and the cover 14 may be pivoted closed as previously described. The clamps 24 may be actuated to tightly lock the cover 14 to the base 16 as previously described.

The devices 74 in the ram unit may then be actuated to force the plunger 72 against the inserts 84 and composition. The inserts 84 and liners 80, 82 and 92 are con structed to prevent the composition from moving out of the cavities 89 between the front and rear dies 86 and 88. The pressure exerted by the devices 74 through the plunger 72 is increased until a given load, e.g., 3500 pounds per square inch, is placed against the surface of the front and rear forming dies 86 and 88. This pressure forces the composition into the given configuration (-FIG. 1). The given pressure and temperature are respectively maintained on the dies 84 and composition and the mold 8 for a given curing period of time, e.g., one-half hour. At the end of the curing period, the pressure exerted by devices 74 is released. Platen 62 is then raised by devices 68 and the locking pressure exerted by clamps 24 is released. Pressure is again exerted on plunger 72 and the formed composition in cavity 89 and the inserts 84 are pushed out of the cavity 18 through the rear end 58. The cover 14 may then be opened, plunger 72 retracted, liner 92 removed, platen 62 closed and inserts 84 reinserted into the cavity 18 to produce another set of brake shoes in a similar manner. It is also contemplated that the configured material in cavities 89 may be removed by pivoting cover 14, removing top liner 92, and lifting the formed composition out of the cavity.

It should be noted that pre-coated metal brake shoe backs (not shown) of known design may be inserted between the composition and the front die 86 prior to applying pressure by devices 74. Upon exerting pressure on the composition and the metal backs, a bonding action will occur. If desired, the configured composition previously described may be secured to metal backs in a known manner after forming.

The compositon may be any one of a number of known heat curable materials used in making friction brake shoes. These materials generally include a thermosetting adhesive and a base material having a high coeflicient of friction.

What is claimed is:

1. A press for making brake shoes having a composition body secured to a metal backing plate, the press comprising: a mold having a longitudinal cavity defined by two pairs of opposed flat surfaces, the opposed flat surfaces of each pair being equally spaced throughout their length; inserts slideably engaged in the longitudinal cavity and movable therethrough, the inserts together with the two pairs of fiat surfaces completely defining a plurality of individual molding cavities, each insert intermediate molding cavities having one surface defining the curved forward surface of one brake shoe and another surface conforming to the metal backing plate of another brake shoe; plunger means slideably engaged in the longitudinal cavity; and power means for moving the plunger means through the longitudinal cavity to move the inserts toward one another and reduce the longitudinal dimension of each individual molding cavity whereby composition material located in each molding cavity will be forced along the fiat surfaces and compressed between the inserts to form composition bodies in each molding cavity.

2. The press set out in claim 1 wherein: end means encloses one end of the longitudinal cavity, the plunger means is slideably engaged with the other end of the longitudinal cavity; and the power means force the plunger means toward the end means to slide the inserts toward one another.

3. The press set out in claim 2 wherein said end means comprises: a movable member enclosing said one end of said longitudinal cavity; and means to raise and lower said movable member to respectively open and enclose said one end of said longitudinal cavity.

4. The press set out in claim 1 wherein said longitudinal cavity is partially defined by a cover and a base: and including means to pivot said cover relative to said base to expose said longitudinal cavity.

5. The press set out in claim 4 including means to tightly engage said cover with said base.

References Cited UNITED STATES PATENTS 131,626 9/ 1872 Noyes et a1. 18-TTdig 660,638 10/1900 Holbrook et a1. 1817P 1,548,537 8/1925 MacDonald 1817P 1,614,601 l/1927 Davis 1820S 1,677,200 7/1928 Oakley 18-17P 1,875,712 9/1932 Duval 18-TTdig 2,347,600 4/ 1944 Goode 18TTdig 2,790,206 4/ 1957 Cofek 184CX 2,943,347 7/ 1960 Archibald 1'8T1"dig 2,943,353 7/1960 'Fraula 18-TTdig 3,078,506 2/1963 Caughey 18-4P 3,082,682 3/1963 Kaufman l8l6M 3,161,912 12/1964 Wiles et a1 18-T1dig 3,189,427 6/1965 Schirm 1843X 3,323,173 6/1967 Poyner 18---43X 3,421,184 1/1969 Ford et al 18-43 J. HOWARD FLINT, 111., Primary Examiner US. Cl. X.R.

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